Apparatus for assembling erasers with holders therefor



Feb. 3, 1959 R. c. HEFFERNAN APPARATUS FOR ASSEMBLING ERASERS WITH HOLDERS THEREFOR Filed June 20, 1955 2 Sheets-Shea t 1 3 M w H 1959 R. c. HEFFERNAN 2,87

APPARATUS FOR ASSEMBLING ERASERS WITH HOLDERS THEREFOR Filed June 20, 1955 2 Sheets-Sheet 2 ffgA/fy United States Patent APPARATUS FOR ASSEMBLING ERASERS WITH HOLDERS THEREFOR Application June 20, 1955, Serial No. 516,361

3 Claims. (Cl. 78-82) This invention relates to means for assembling an eraser and its holder and, more particularly, to an apparatus for assembling an eraser holder with a rotatable eraser.

Erasers which are mounted in holders are preferably rotatable within the holder, so as to allow the full usage of the eraser material. A popular form of eraser, which is held in a holder, is the annular typewriter eraser and its companion brush. Typewriter erasers are mounted in holders which also carry a. brush and relatively stiff bristles. The brush protrudes from the holder, so as to-be disposed away from the eraser. The eraser is rotatable within the holder so that it may be revolved both with relation to the holder and to the brush fixed inthe holder. This rotation is desired to permit positioning of various parts of the eraser with relation to the extended brush portion. Thus, the brush which serves as a form of handle and its accompanying eraser, can be relatively rotated to permit the most effective disposition of the eraser, the holder and the brush, while employing a desired peripheral area of the eraser'for erasure.

' In using an eraser to abrade a small area, a high degree of control of the erasing surface is necessary to attain the desired result. Consequently, effective control is established by relative rotation of the eraser and the holder to provide a proper grip on the eraser and control of the erasing'surface. An easy movement between the eraser and the holder is thus highly desirable. At'the same time, the holder must grip the eraser frictionally to avoid free rotation whichwould militate against good eradicating action. The holder must tend to hold the eraser relatively stationary except under a strong urging. In the assembly of erasers, such as typewriter erasers and suitable holders, it isdesirable to accomplish the joining of the eraser and holder by wholly automatic means. At the same time, it is desirable to provide the free relative rotatability mentioned above.

It is an object of this invention to provide an eraser and eraser holder assembly in which the eraser is held relatively rotatably in a holder which is attachedto said eraser by an automatic action.

It is another object of this invention to provide a means and method for attaching an eraser holder to an eraser by a structure which permits the eraser to rotate with ,the eraser is automatically fed into the means for assembling the eraser on the holder. and is automatically positioned in said means to allow an assembly of the eraser and the holder in which the eraser is rotatable with relation to the holder.

This invention has as a further object, the provision of dies for joining surfaces of an eraser holder-to form an axis or hub on which the eraser may rotate.

It is still another object of thisinvention to provide ICC.

means for joining two parts of an eraser handle with respect to said eraser such that the eraser may rotate with relation to the eraser holder and the joined parts of the eraser holder have the appearance of a rivet around which the eraser rotates.

These and other objects of this invention will become more apparent upon consideration of the following description, taken together with the accompanying drawings, in which:

Fig. 1 is a front elevation of a chain drive and associated parts of this invention, partially in section and with parts removed;

Fig. 2 is a front elevation of a finger and finger holder of the assembly apparatus, holding an assembled eraser and eraser holder;

Fig. 3 is a front elevation of an assembled eraser and eraser holder;

Fig. 4 is a sectional view on line 44 of Fig. 3;

Fig. 5 is a plan view of an eraser holder blank;

Fig. 6 is an end view of the chain drive of Fig. 1 and the eraser feed taken on line 66 of Fig. l;

Fig. 7 is a top view of the opposing dies against an assembled holder and eraser; and

Fig. 8 is a face elevation of the working end of a die of this invention.

This invention generally provides an apparatus for assembling an eraser and an eraser holder such that a portion of the eraser holder forms an axis around which the eraser may be rotated but at the same time forms a surface which frictionally holds the eraser against free rotation in the holder. The apparatus for assembling the eraser and holder is provided with means for forming an axis in the holder on which the eraser may rotate.

Referring specifically to the figures, Fig. l shows a chain drive 10 which carries on its links bases 11. Each of the bases 11 supports a finger holder 12 on which is mounted a pair of fingers 13 and 14. The relation of the base 11 and finger holder 12 is shown in greater detail in the enlarged view of Fig. 2. The base 11 is carried on a chain link 15. The finger holder 12 sits in the base 11 and is held in a firm relationship by tapered interfitting surfaces of the base 11 and the holder 12. The finger 13 is pivotally mounted on the holder 12 by a finger pivot pin 16. The finger 14 is integral with the holder 12 and provides a fixed member with respect to the pivotal finger 13. The pivotal finger 13 is maintained in a downward position, as seen in Fig. 2, by a tension spring 17 which is connected between a downwardly extending tongue 18 on the pivotal finger 13 and a lug 19 on the holder 12.

The fingers 13 and 14 serve to clasp an eraser holder 20 of the eraser and holder assembly. Fig. 3 shows one embodiment of an assembled eraser 21 and the holder 20 of this invention, with an accompanying brush 22.

Fig. 4 shows a sectional view of this embodiment of the assembled components. A stamped blank 23 from which the holder 20 is formed by folding is shown in the plan view of Fig. 5. The blank 23 is composed principally of two lobes 24 extending from a central portion 25. The holder blanks 23 positioned between the fingers 13 and 14 on the chain drive 10 are folded to form a U-shaped member. The folded holder 20, formed from the blank 23, is passed through a series of operations which prepare the holder 20 for assembly and whichassemble the holder with a brush 22. At an assembly unit 26, the eraser 21 is assembled with the holder 20 to provide the finished assembled eraser and holder, as shown The eraser 21 is mounted in the eraser holder 20 by the joinder of the two lobes 24 of the blank with a coldweld. The coldweld is effected in a pressure operation which results in a union of the lobes 24. The coldweld is made by the action of a pair of dies 27 in the assembly unit 26. The unit 26 is shown in Fig. 6 in a view taken perpendicularly to the chain drive 16 and axially of the hydraulic cylinders, not shown, which provide the power for operating the dies 27 The dies 27 are mounted in respective die holders 28 which, in turn, are mounted for reciprocation in respective hydraulic cylinders, not shown. The die holders 28 are axially movable in respective bearing rings 29 which support and guide the die holders28 in their movement. The respective die holders 28' and the dies 27 move diametrically under hydraulic pressure to approximate a contacting position directly over the chain drive 10.

As shown in Fig. 1, the holders 26 approach the unit 26 folded to a position where the lobes 24 stand upright and with the brush 22 inserted and fastened in each holder. As the brush-carrying holders 2% move into the assembly unit 26 on the finger holder 12 by the movement of the chain drive 10, the movement of the holder 20 carried by the finger holder 12 is synchronized with the operation of the assembly unit 26 to position the holder 20 for the reception and mounting of the eraser 21 at the proper time interval. Y

The synchronized motion of the chain positions each holder in the assembly unit 26, so that the erasers 21 can be fed into the positioned holders 29 from a guide chute 39, as shown in Figs. 1 and 6.

When the finger holders 12, carried by the chain drive 10, are properly positioned in the assembly unit 26, actuation of the hydraulic cylinders moves the die holders 2% and effectuates the closing of the dies 27. The dies 27, moving diametrically, squeeze the holder 20 between their confronting surfaces through an aperture in the eraser 21, as shown in Fig. 7. The aperture 36) in the eraser 21 is dimensioned to receive the protruding bosses 56 of the dies 27 and the material of the holder 20 which is caught between the dies 27 and their bosses 56. The bosses 56 have an abbreviated cone shape with a central recess 57 at the middle of the cone surrounded by an annular rim 58, as shown in Fig. 8. The rim 58 stands out slightly from its next adjacent radial surface 59 on each of the dies 27. A cone-shape surface 60 forms the truncated cone aspect of the bosses 56 for each of the dies 27. The dies 27 are shaped to form a flat topped cone 31 in each of the lobes 24 during the metal working operation. The aperture 39 and the bosses 56 are correlated in size so that the cones 31 of the holder 20 will fit into the aperture 31 in the completely as sembled finished product, as shown in Fig. 7.

The cross-sectional configuration of the joint between the lobes 24, formed by the dies 27, is shown in Fig. 7

in an enlarged view of the holder 2%, taken radially of the eraser 21. The dies 27 are shown in a closed or pressed together position. The coldweld action of dies 27, which is described in greater detail below, forms the metal of the lobes 24 at the union between the two lobes. lobes 24 are formed into a symphysis of the metals of the two lobes 24 by a coalescence under the pressure of the diametrically moving dies 27. Radially within the symphysis, formed by the annular rims 58, the metal is formed into a globule 62. The globule 62 forms a pair of hemispherical protuberances on the outer surface of the holder 20, as shown in the finished product in Figs. 3 and 7. Immediately surrounding the protuberances $5, the rims 58 form annular grooves 63 in the outer surface on each side of the holder 2%). Next radially adjacent the groove 63 on the two outer surfaces of the holder 20 are fiat rings 64. The rings or terminate in the inwardly tapering conical walls 36. The rings' and the walls 36 are formed by the annular surfaces 52 and the coneshaped surfaces 6%, respectively, of the dies 27.

The dies 27 in forming the fiat topped cones 31 with their oblique walls 36, form two halves of an hour glass shaped hub 65, and are joined at the symphysis 59 as seen in Fig. 4. The facing inner surfaces of the lobes 24 are formed into a V-sh'ziped groove 66 at the hub 65.

The I This V-shaped groove is delineated by the walls 36 of the abutting flat topped cones 31. The eraser 21 contains the hub 65 in its central aperture 30 and is thus securely mounted on the holder 2t).

In assembling the erasers 21 in the holders 20 to provide the finished product of Fig. 3, the erasers 21 and the holders '20 must be simultaneously and properly positioned in alignment with the axis of the dies 27 and their holders 28. As shown in Figs. 1 and 6, to achieve this simultaneous interpositioning of each eraser 21 between the lobes 24 of one of the holders 29, which, in turn, is accurately positioned axially of the dies 27, the erasers are fed into position in the assembly unit 26 through a guide chute 32 which contains side guides 33 and end guides 34 and 37. There is also provided at the lower end of the chute 32, a pair of fingers 3S and 39 for holding the erasers 21 in position during the coldweld operation. The rear fingers 38 and 39 are shown in Fig. 1. Thus, the erasers 21, fed through the chute 32, are held on all four sides as they descend from a suitable feeding device, not shown. The erasers are fed under the pull of gravity and abut against each other as they descend the chute 32, so that each of the erasers 21 in the chute 32 supports the next superior eraser in its descent through the chute 32.

The side guides 33 terminate immediately above the diametrically positioned ends of the die holders 28, as shown in Fig. 6. Thus, the bottom end of the side guide 33 serves to hold the lateral surfaces of the erasers 21 when positioned between the dies 27.

As shown in Fig. 1, the erasers 21 are held radially by the fingers 38 and 39. Thus the chute 32 serves to hold the erasers 21 in aligned position during the eraserholder assembly operation. The erasers 21 are fed into position for assembly, one at a time, through the operation of an eraser feed rnechanism. The eraser teed mechanismcenters around a rocking feed finger 40. The

feed finger 40 turns on a pivot pin 41 mounted in a guide support 42 and is rocked by the movementof a solenoid bar 43 to which it is attached by a connecting pin 44. The feed finger 40 has an angular lower end which extends obliquely into the guide chute 32 through a slot 45. A vertical surface 46 at the lower end of the finger 40 moves into the slot to be abuttable against the erasers 21 descending in the chute 32. The angular end of the finger 40 swings with the oscillation of the finger 40 to be engageable and disengageable with the descending erasers 21. Thus, the finger 40, through its surface 46, alternately jams and releases the descending erasers 21 within the chute 32.

The feed finger 40 is rocked by the opposing'actions of a push-type solenoid 47 and a tension spring 48. The tension spring 48 is anchored to a pin 49, which, in'turn, is mounted on the table 50 of the hydraulic mechanism. The other end of the tension spring 48 is attached to a. connecting pin 51 on the solenoid armature 52. The tension spring 48 tends to pull the armature 52 out of the solenoid 47 and to rock the feed finger 40 with a counterclockwise motion away from engagement with erasers 21 in the chute 32. Energization of the solenoid 47, on the other hand, pulls thearmature 52 into the position shown in Fig. 6, against the tension spring 48 and holds the surface 46 against the eraser 21 in the chute 32.

The solenoid 47 is actuated by any suitable switching means to coordinate the feed of the erasers 21 with the arrival and positioning of the holders 20 on the axis of the dies 27. One method of timing the release of the erasers 21 may be accomplished by interrupting a light beam with the brush on the holder. The interrupted light beam, by creating a pulse from a photoelectric cell, may create acontrol'signal for the de-energization of the solenoid. With the solenoid de-energized, the tension spring 48 will operate to pull the core 52 out of the sole- "noid 47 arid through" the's'ole'noid bar 43" cause the feed finger 40 to rock counterclockwise and release an eraser erasers 21 in the guide chute 32.

At the completion of the eraser and holder assembly operation, the timed motion of the chain will move the assembled product from the assembly unit 26. As shown in Fig. 1, the front finger 39 is mounted on a pivot 53 and held in an eraser stabilizing position by a compression spring 54. As the assembled eraser and holder are moved from the unit 26, by the chain drive 10, the eraser 21 bears against the front finger 39 and causes it to tilt against the pressure of the spring 54. After the assembled eraser-holder is moved from the unit 26, the finger 39 snaps back into position to steady the next succeeding eraser 21 during its assembly operation.

The forming of the metal union by the cold-weld operation results in a working of the metal which provides the radial section of the union shown in Fig. 7. In this working of the metal by the dies 27, the worked metal is stretched, in part thinned down in the area oflthe symphysis 59 and forced into the globule 62. The metal working, therefore, produces two results. It forms the hub 65 with its V-shaped groove 66 engaging the eraser 21 and it forms the globule 62 which provides the rivet-like protuberances 35. It also effects a firm bond between the two lobes through the coalescence of the metals of the two lobes between the opposing annular rims 58.

After the assembly of the eraser 21 in the holder 20, the finger holder 12 carried by the chain drive 10, moves over a sprocket 55 and is tilted to point the fingers 13 and 14 downwardly toward a hopper 67. The pivoted finger 13 is provided with a rearwardly extending dog 68. The dog 68 is positioned to strike a cam abutment 69 when the fingers 13 and 14 are properly located. The engagement of the dog 68 with the abutment 69 serves to force the fingers 13 and 14 apart and allow a stripper to strip the finished, assembled eraser, brush and holder ofi the finger and into the hopper 67.

The eraser 21 is rotatable on the hub 65 with relation to the holder 20. However, the V-shaped groove 66 serves to grip the eraser 21 at the aperture 30 and prevent unrestricted rotary movement between the holder '29 and the eraser 21. Thus, the eraser 21 is rotatable on the holder 20, but will retain its position against free rotation in the absence of positive effort to rearrange the relationship between the eraser and the holder. There is thus provided by this invention a combined eraser and holder in which the holder retains the eraser in combination by a coldweld between two parts of the holder, and, :at the same time, provides a shape to the union between its parts which allows easy repositioning of the eraser with relation to the holder. This independence between the eraser and the holder, coupled with the secure mounting of the eraser on the holder, provides the product of this invention with many advantages.

As was noted above, the eraser can be easily rotated with relation to its holder, so as to provide a full range of surfaces for erasure. At the same time, the relation between the eraser and the holder is not so free as to cause the eraser to spin or slip on the holder.

Another advantage of the invention is seen in the appearance, as shown in the side view of Fig. 3. The forming of the metal by the coldweld does not deface the product or detract from its appearance. The protu 6 berances 35 on each side surface of the lobes 24 have the appearance of arivet" which with certain esthetic values.

Another advantage in the device of this invention-is; found in the comfortable grip provided by the central") depression in the lobes 24. This depression created by the forming of the fiat top cones 31 allows the holder to be gripped with greater ease and comfort during the erasure. l

The assembly operation of this invention provides simplified means for producing an eraser, brush and holder combination with a minimum of manual labor and supervisory control and a-maximum automation. The combination of the eraser 21 and the holder 20 in the assembly unit 26, as described above, is a' completely automatic operation. The resultant structure is attractive in appearance and useful, as described above, with a minimum of surplusage and waste. The configuration of the radial sectionof the union between the two lobes of the holder, as describedabove, provides a structure,

which is novel and useful.

Symphysis as'used in the above description refers to the combination of the two parts of the holder into one body by the coldwelding.

It will be understood that the above described embodiment of the eraser and holder combination isset forth only for the purpose of illustration. Various modifications may be made of the specific features while retaining the basic structure and functions of this invention. Such variations are within the spirit of this invention and it is intended that this invention be limited only by the scope of the appended claims.

What is claimed is:

1. In a machine for assembling an eraser and a metallic holder therefor, a work clamp adapted to grip an eraser holder having a pair of spaced parallel side walls designed to receive an annular eraser therebetween, an eraser feeding guide located in the plane of said work clamp whereby an eraser holder in said clamp is presented to said feeding guide, means for discharging an eraser from said feeding guide into an eraser holder carried by said work clamp, and a pair of spaced cold Welding pistons adapted to inwardly deform the side Walls of an eraser holder in said work clamp and form therein a supporting hub for an eraser discharged thereinto from said feeding guide, said pistons being mounted between said feeding guide and said work clamp to reciprocate into and out of contact with an eraser holder positioned between the confronting faces of said pistons by said Work clamp.

2. In a machine for assembling an annular eraser and -a metallic holder therefor, a plurality of work clamps adapted to grip a metallic eraser holder having a pair of spaced parallel side walls designed to receive an annular eraser therebetween, an open ended eraser feeding guide adapted to contain therein a plurality of annular erasers in superimposed peripheral contact for discharge therefrom through the open end thereof, means for successively aligning said work clamps with the open end of said eraser feeding guide whereby eraser holders in said clamps are presented to the open end of said feeding guide, means for discharging an eraser from the'open end of said feeding guide into an eraser holder carried by an aligned Work clamp, a pair of spaced cold welding pistons adapted to inwardly deform the side walls of an eraser holder in said work clamps and form therein a supporting hub for an eraser discharged thereinto from said feeding guide, said pistons being mounted in alignment between the open end of said feeding guide and said clamps to reciprocate into and out of contact with an eraser holder positioned between the confrontin faces of said pistons by said work clamps.

3. In a machine for assembling an annular eraser and a metallic holder therefor, a plurality of work clamps adapted to grip a metallic eraser holder having a pair of provides 7 the product spacedparallel sidewalls designed to receive an annular eraser therebetween, an open ended eraser feeding guide adapted to .contain' therein a plurality of annular erasers in superimposed peripheral contact for discharge therefrom through the open end thereof, means for successively aligning said work clamps with the open end of said eraser feeding guide-whereby eraser holders in said clamps are presented to the open end of said feeding guide, an eraserfeed regulating element mounted adjacent said eraser feeding guide, means normally biasing said element into restraining contact with an eraser in said feeding guide; an actuator connected to said feed regulating element adapted to withdraw said element from eraser restraining contact whena work clamp and said feeding guide are in alignment with each other whereby an eraser is fed into an eraser holder in said work clamp, a pair of spaced. cold welding pistons adapted to inwardly deform the side walls of an eraser holder in said work clamps and form therein a supporting hub for an eraser discharged thereinto from said feedingv guide, said pistons being mounted in alignment between the open end ofsaid feeding guide and said i References Cited in the file of this patent UNITED STATES PATENTS Re. 18,963 Corey- Oct; 3, 1933 1,381,810 Dayton June 14, 1921' 1,681,512 Beyer Aug. 21, 1928 1,961,429 Perret June 5, 1934- 2,054,163 Meilner Sept. 15, 1936 2,386,948 Hanley Oct. 16, 1945' 2,396,412 D'onistherorpe Mar. 12, 1946 2,527,479 Hall Oct. 24, 1950 2,603,987 Lyon July 22, 1952 2,630,172 Hofmeister Mar. 3, 1953' 2,639,633 Sowter May 26, 1953 2,639,634 Sowter May 26', 1953v 

